The invention relates to an injection valve of the type described herein and finally claimed. Injection valves are already known in which, during operation with certain kinds of fuel, the ejection opening becomes constricted, particularly in internal combustion engines with exhaust gas recirculation. The constriction which results between the cooperative elements is due in part to accumulation of deposited foreign material and in part to corrosion which in turn is also affected by the deposits. The constriction of the ejection opening results in an error in the fuel injection quantity, which not only affects the running of the internal combustion engine and the exhaust composition but also can cause the engine to eventually stop.
In other known injection valves of the type described, nozzle bodies and nozzle needles are manufactured from high-quality steel, which, because of the inferior hardness attainable in corrosion-resistant steels, causes higher wear at the valve seat, particularly at the areas of the nozzle body and needle subjected to impact and thus results in a shorter operational life of the valve. Furthermore, the expense is greater with these steels because of higher raw-material costs and the poorer machining capacity of these steels.